Guide chains for feed lines

ABSTRACT

A feeder chain for the supply of all types of consumable material to units that move on tracks. The chain comprises a plurality of chain links and has a continuous inner space for feed lines, whereby the chain links have pivotably interconnected outer side pieces that are provided with stops for delimiting the mutual pivot angle. Each chain link is provided with two detachable crosspieces for interconnecting the outer side pieces thereof. The crosspieces are tubular pieces that are insertable via a force fit onto projections of the outer side pieces.

BACKGROUND OF THE INVENTION

The present invention relates to a guide or feeder chain for the supplyof all types of consumable material to units that move on tracks, withthe chain comprising a plurality of chain links and having a continuousinner space for feed lines, whereby the chain links have pivotablyinterconnected outer side pieces that are provided with stop means todelimit the mutual pivot angle, with each chain link being provided withtwo detachable crosspieces for interconnecting the outer side piecesthereof.

German Patent No. 19 32 428 discloses a feed chain where the side piecesof the chain links are integrally interconnected by a crosspiece thathas an opening for the feed lines. With this known feed chain, theability to receive feed lines is limited by the size of the opening inthe crosspiece. When the capacity of the feeder chain has beenexhausted, another chain with completely new chain links must be madeavailable, so that with this known state of the art, the manufacturingand storage expenses are particularly high due to the differentrequirements that result during use.

Due to the aforementioned reasons, feeder chains of the initiallymentioned type have become known where the width of the chain links, andhence the width of the inner space that receives the feed lines, can bechanged by exchanging or altering detachable crosspieces thatinterconnect the outer side pieces of the chain links. German Patent No.37 30 586 discloses a link chain of this type where the crosspieces, inorder to effect the detachable connection of the outer side pieces, eachcomprise a central portion of adjustable length, and two end pieces thatcan be securely connected thereto and that cooperate with the outer sidepieces of the chain links. Unfortunately, this construction isrelatively expensive, because each crosspiece is formed from threerelatively complicated individual parts, with the two end pieces beinginsertable into the ends of the central portion in order to form alocking connection therewith. In addition, the ends of the end piecesthat are connectable to the outer side pieces are embodied as expensiveplug-type elements for a locking connection, and can furthermore beprovided with a screw connection to the outer side pieces.

German Patent No. 22 55 283 discloses a feeder chain having separablecrosspieces comprised of at least two traverses and separating elementsthat are disposed therebetween. With this known feeder chain, thetraverses have a flattened crosssectional configuration with rounded-offnarrow sides, with gated recesses that are provided with undercuts beingdisposed on the upper and lower ends of the separating elements, so thatafter being placed into the recesses, the traverses can be secured in apositive and form-locking manner with the separating elements by beingtwisted about their longitudinal axes.

Proceeding from the above, it is an object of the present invention toprovide an improved guide or feeder chain that has detachablecrosspieces, whereby in particular the construction of the crosspieces,and their connection with the outer side pieces, is simplified.

BRIEF DESCRIPTION OF THE DRAWINGS

This object, and other objects and advantages of the present invention,will appear more clearly from the following specification in conjunctionwith the accompanying schematic drawings, in which:

FIG. 1 is a partially cross-sectioned side view of one exemplaryembodiment of the inventive feeder chain;

FIG. 2 is a perspective exploded view of a chain link of the feed chainof FIG. 1;

FIG. 3 shows another exemplary embodiment of an inventive chain linkwhere the position of a longitudinally slotted and an unslotted tubularpiece, as well as the associated projections, have the reverse positionof that of the embodiment illustrated in FIG. 2;

FIG. 4 is a perspective view of the chain link of FIG. 3, with thelongitudinally slotted tubular piece being removed for insertion of feedlines;

FIG. 5 shows the chain link of FIG. 4 with the longitudinally slottedtubular piece having been inserted;

FIG. 6 is a perspective view of a chain link of another exemplaryembodiment of the inventive feeder chain where a longitudinal slot isdisposed on one flattened outer side of a tubular piece, and thislongitudinally slotted tubular piece is removed;

FIG. 7 is a perspective exploded view of a connector of the feeder chainof FIG. 1 for securement to a fixed connector;

FIG. 8 is a perspective exploded view of a connector of the feeder chainof FIG. 1 for securement to a movable consuming device;

FIG. 9 is a perspective exploded view of a chain link having analternative securement for the tubular piece in recesses of the outerside pieces;

FIG. 10 is a perspective view of the chain link of FIG. 9 with thetubular piece inserted;

FIG. 11 is a longitudinal cross-sectional view of the chain link of FIG.10 showing the tubular piece partially inserted into the recess; and

FIG. 12 is a longitudinal cross-sectional view of the chain link of FIG.11 with the tubular piece completely inserted, with a tool being shownin place on the tubular piece.

SUMMARY OF THE INVENTION

The guide or feeder chain of the present invention is characterizedprimarily in that the crosspieces that interconnect the outer sidepieces of a chain link are tubular pieces, at least one of which isinsertable via a force fit onto projections that are provided on theouter side pieces.

Thus, with a feeder chain constructed pursuant to the present inventionthe crosspieces are formed by tubular pieces, the hollow interior ofwhich, at least in the end regions, receives projections that areintegrally formed on the inner walls of the outer side pieces. In thisconnection, the interior of the tubular pieces is undersized while theoutside of the projections is oversized, so that when the tubular piecesare inserted on the projections, a force fit, i.e. a secure connection,results. As an alternative, the force fit can also be produced via ashrink fit of the tubular pieces.

The present invention has the advantage that the crosspieces can be cutto length from conventional tubes for a respective need, whereby notonly plastic but also metallic tubes can be used. Thus, with the presentinvention it is not necessary to use different tools, especiallydifferent extrusion dyes, to produce different crosspieces for thefeeder chain. In addition, the structural expense with regard to theouter side pieces of the chain links is also low, because it is merelynecessary for these outer side pieces to have projections that have astraightforward, smooth shape. Finally, the assembly and removal of thechain links is also simplified because for this purpose it is merelynecessary for the tubular pieces to be placed or pressed upon theprojections or to be pulled therefrom. The assembly or removal can beeven further simplified by using a simple pressing device.

Pursuant to one preferred specific embodiment of the present invention,the tubular pieces, while having an approximately constant thickness,are flattened on two oppositely disposed outer sides, and arerounded-off on two other oppositely disposed outer sides, with thedistance between the flattened outer sides being less than the distancebetween the rounded-off outer sides; the corresponding projections havetheir flattened outer sides disposed parallel to the longitudinal narrowsides of the outer side pieces. As a consequence of this construction, afeeder chain having a relatively large inner space for feed lines isprovided because the tubular pieces, which have their flattened sidesoriented in the longitudinal direction of the chain, take up only asmall portion of the height of the chain links due to the relativelysmall distance between the flattened sides of the tubular pieces. At thesame time, a very strong and torsionally rigid connection is achievedbetween the outer side pieces of the chain links, especially because therelatively great distance between the rounded-off outer sides of thetubular pieces brings about a relatively high moment of resistance, andin the region of the flattened outer sides a large contact surfaceexists between the tubular pieces and the projections.

Pursuant to one practical specific embodiment, each chain link isprovided with one tubular piece that has a longitudinal slot, and oneunslotted tubular piece, whereby the longitudinally slotted tubularpieces of all of the chain links are disposed on only one side of thechain. The slotted tubular pieces can be easily widened and withdrawnfrom the projections of the outer side pieces, as a result of which oneside of the feeder chain can be opened to permit simple placement offeed lines therein. For this purpose, it is not necessary to press theouter side pieces apart, as is the case if only unslotted tubular piecesare used and the projections have the same length on both sides of thechain. When the feed lines are placed in the chain, the longitudinallyslotted tubular pieces of the completely assembled feeder chainessentially serve to guide the feed lines, although they also contributeto the stability of the chain links. However, the unslotted tubularpieces make a greater contribution to the stability because theseunslotted tubular pieces are subjected to practically no deformationunder load.

With a feeder chain having tubular pieces that are flattened on twoopposite outer sides and are rounded-off on two other opposite outersides, the longitudinal slot is preferably disposed on a rounded-offside of the tubular piece, so that the longitudinally slotted tubularpiece can be withdrawn in the longitudinal direction of the feeder chainwithout entering into the inner spaces of the link chain occupied by thefeed lines.

The inventive feeder chain can also be easily opened for placing feedlines therein if the longitudinal slot is disposed on a flattened outerside of the tubular piece and has approximately the same dimension inthe longitudinal direction of the link chain. Due to the considerablespan of the longitudinal slot, the tubular piece can be easily pressedonto or withdrawn from the projections in a direction perpendicular to aplane that passes through the joints of the chain when it is in astretched or extended condition. The tubular pieces are preferablyinstalled in such a way that the longitudinal slots are open in adirection toward the interior of the link chain, so that when they arebeing pressed on or withdrawn, the tubular pieces do not have to beintroduced into the inner space of the chain. If in addition arounded-off outer side of the tubular piece has a longitudinal groove,the tubular piece can be removed from the projections by introducing ascrewdriver into the longitudinal groove.

Pursuant to another practical embodiment of the present invention, theprojections of the outer side pieces that ar associated with thelongitudinally slotted tubular pieces are shorter than the projectionsthat ar associated with the unslotted tubular pieces, so that thecross-sectional area that is available for the introduction of feedlines is relatively large when the longitudinally slotted tubular piecesare removed from the link chain.

Pursuant to a further specific embodiment of the present invention, theend links of the chain that form the connectors have a tubular piecethat connects the outer side pieces and that is provided with asecurement tongue for securement to a fixed connection or a movableconsuming device. The securement tongues enable the transfer of forceover a large surface between the feeder chain and a connection orconsuming device that withstands the entire chain weight and the dynamicstresses that occur during operation.

Pursuant to an alternative embodiment of the inventive feeder chain fora simple opening for the placement of feed lines therein, one of the twocrosspieces that is embodied as a tubular piece is adapted to beinserted into gated recesses of the outer side pieces that are providedwith undercuts. The dimensions between the tubular pieces and therecesses can be such that after being placed in the recesses, thetubular pieces can be secured with the outer side pieces in a positiveand form-locking manner .[.by being twisted about their longitudinalaxes.]..

The connection between the other tubular piece and the outer side piecesis effected in the same manner as with the preceding embodiments.

Finally, it is proposed pursuant to another specific embodiment of thepresent invention, that the tubular pieces be made of a lightweightmetal, so that a very stable feeder chain can also be achieved whileproviding a lightweight chain.

Further specific features of the present invention will be described indetail subsequently.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings in detail, the guide or feeder chainillustrated in FIG. 1 comprises a number of chain links 1 as well as aconnector 2 for a movable consuming device and a connector 3 for a fixedconnection. On those ends 4 of its outer side pieces 5 that ar disposedmore closely together, each chain link 1 is provided with pins 6,whereas those ends 7 of the outer side pieces 5 that are disposedfurther apart are provided with corresponding holes 8. The pins 6 ofeach chain link 1 extend into holes 8 of an adjacent chain link or intocorresponding holes 9 of the outer side pieces 10 of the connector 2(see FIG. 8). The connector 3 for the fixed consuming device is providedwith appropriate pins 11 on outer side pieces 12 (see FIG. 7), withthese pins 11 engaging in corresponding holes 8 of the adjacent chainlink 1.

In addition, the outer sides of the closer together ends 4, and theinner sides of the further apart ends 7, of the outer side pieces 5 areprovided with stop means 13, 14 (see FIG. 2) that have abutment edgesthat extend radially relative to the axes of the holes 8 and the pins 6.The stop means 13 of the further apart ends 7 cooperate with thosedelimiting walls of notches 15 on the closer together ends 4 of theouter side pieces 5 that extend radially relative to the pins 6, whereasthe stop means 14 cooperate with those delimiting walls of cutouts 16 onthe inner walls of the further apart ends 7 of the outer side pieces 5that extend radially relative to the holes 8. As shown in FIG. 1, whenthe guide or feeder chain is bent, each chain link 1 attains relative tothe adjacent chain link 1 a specific pivot angle whereby the delimitingwalls of the stop means 13 rest via a large surface area against thedelimiting walls of the notches 15, thereby preventing a furtherbending. Since the delimiting walls of the stop means 14 (notillustrated) also rest against the delimiting walls of the cutouts 16 atthe same pivot angle, the transfer of force between the adjacent chainlinks is improved. In contrast, when the feeder chain is disposed in itsextended state, the other delimiting walls of the stop means 13, 14 restagainst the other delimiting walls of the notches 15 or cutouts 16. Thisstate has been attained by the two bottom chain links of the feederchain illustrated in FIG. 1.

As shown in FIGS. 1 and 7, the connectors 3 are provided with notches17, those delimiting walls of which that extend radially relative to thepins 11 being angularly spaced from one another in such a way as tocorrespond to the angular spacing of the radial delimiting walls of thestop means 13. As a result, the adjoining chain link 1 cannot bendrelative to the connector 3. The two notches 17, which are offsetrelative to one another by b 90°, enable a mounting of the connector 3on a fixed connection at an offset angle of 90°. Due to the symmetricalconstruction of the connector 3, this connector can in addition berotated at every angular position in such a way that each of its outerside pieces 12 cooperates with another outer side piece 5 of theadjoining chain link, resulting in considerable variation with regard tohow it can be mounted.

The same is true for the connector 2, which as shown in FIG. 8 has twocutouts 18 that are offset by 90° and are provided with delimiting wallsthat extend radially relative to the holes 9. The angular spacing of thedelimiting walls and the cutouts 18 again coincides with the angularspacing of the radial delimiting walls of the stop means 14 of the chainlinks 1, so that with every assembly arrangement of the chain link 1 onthe connector 2, these two components cannot pivot relative to oneanother. Again, the connector 2 can be mounted in four different waysrelative to the chain link 1, resulting in considerable variationrelative to the mounting of the connector 2 on a movable consumingdevice.

It should be noted that all of the pins 6, 11 have an inclined surface19, 20 so that the pins can easily be inserted into the holes 8, 9 ofthe adjoining chain link 1 or connector 2, so that it is merelynecessary to overcome a crosspiece between the cutouts 16, 18 and theholes 8, 9, whereby it is also possible to chamfer these crosspieces inthe direction of insertion.

As shown particularly clearly in FIG. 2, the two edges of the inner wallof the outer side pieces 5 are respectively provided with a longprojection 21 or a short projection 22. Placed on the integrally moldedprojections 21, 22 are unslotted tubular pieces 23, and tubular pieces24 that have a longitudinal slot 25 on one rounded outer side, wherebythe unslotted tubular pieces 23 are associated with the long projections21. Since the tubular pieces 23, 24 have a force fit on the projections21, 22, these tubular pieces 23, 24 form crosspieces that securelyinterconnect the outer side pieces 5 of the chain links. However, thelongitudinal slot 25 of the tubular piece 24 permits the guide or feederchain to be opened on one side for the insertion of power or feed lines,with this being accomplished by widening the tubular piece 24 at thelongitudinal slot 25 and pressing the tubular piece over the flat sidesof the short projection 22. By providing the tubular pieces 23, 24 withtwo flattened outer sides that are spaced relatively close together, andwith two rounded outer sides that are spaced relatively far apart, ahigh stability of the construction is achieved that at the same timeprovides a relatively large interior space for the disposition of thefeed lines.

As can be seen from FIG. 1 in conjunction with FIGS. 7 and 8, the edgeregions of the outer side pieces 10, 12 of the connectors 2, 3 areprovided with respective projections 26, 27. These projections enterinto a force fit with tubular pieces 28, 29 that are each provided withconnection lugs 30, 31 and holes 32, 33 to enable mounting on a movableconsuming device or a fixed connection. The tubular pieces 28, 29 haveno slots since they must provide a stable connection between the outerside pieces 10 or 12 and because, as a consequence of the fact that thetubular pieces 28, 29 are disposed on only one side of the connectors 2,3, feed lines can be introduced in an unobstructed manner.

With the chain link 34 illustrated in FIG. 3, in contrast to the chainlink 1 of FIG. 2, the short projections 22 and the associatedlongitudinally slotted tubular pieces 24 are disposed on the upper edgeof the outer side pieces 5, whereas the long projections 21 and theassociated unslotted tubular pieces 23 are disposed on the lower edge ofthe outer side pieces 5. In this way, the interior of the feeder chainis accessible from the other side for the introduction of feed lines.

As shown in FIGS. 4 and 5, the chain links 34 are first preassembled bypressing the unslotted tubular pieces 23 onto the long projections 21,thereby already providing a stable chain link. Feed lines can then beintroduced through the large free space that is provided between theshort projections 22. Finally, the chain link 34 is closed by pressingthe slotted tubular piece 24 onto the short projections 22 in thelongitudinal direction of the feeder chain.

FIG. 6 shows a similar chain link 35, the longitudinally slotted tubularpiece 36 of which, in contrast to the longitudinally slotted tubularpiece 24 of the chain link 34, has a longitudinal slot 37 that occupiesapproximately one entire flattened outer side. Via this longitudinalslot 37, the tubular piece 36 can be easily inserted upon the shortprojections 22 of the outer side pieces 5. To remove the tubular pieces36, the same are provided with a longitudinal groove 38 into which canbe placed the blade of a screwdriver in order to lift the tubular piece36 off.

FIGS. 9 to 12 show an alternative embodiment of the inventive guide orfeeder chain, which is provided with chain links 49, the upper side ofthe outer side pieces 5 of which are provided with recesses 50 intowhich a tubular piece 23 can be positively inserted in a form-lockingmanner. For this purpose, the recesses 50 .[.are gated or are.]..Iadd.have gates 55 which .Iaddend.open toward the top(.Iadd.upwardly.Iaddend.) and provided with .Iadd.first and second.Iaddend.undercuts .Iadd.53, 54 .Iaddend.into which the rounded-offnarrow sides of the tubular pieces 23 fit. .Iadd.Each tubular piece 23has a length between opposing ends thereof and a width between a firstlateral surface 56 and a second lateral surface 57 provided at both endsof tubular piece 23. When second lateral surface 57 is positioned in thesecond undercut 54, first lateral surface 56 is insertable into the gate55 via an elastic force-fit when entering throuqh gate 55 into the firstundercut 53. The width of the end of tubular piece 23 between first andsecond lateral surfaces 56, 57 is greater than the width of gate 55,whereby engagement between lateral surfaces 56, 57 and undercuts 53, 54,respectively, retains tubular piece 23 in recess 50. Lateral surfaces56, 57 are rounded-off surfaces forming a shape complementary to theshape of said first and second undercuts 53, 54, respectively.

In the illustrated embodiment, the ends of tubular piece 23 have athickness smaller than the width between the first and second lateralsurfaces 56, 57. Tubular piece 23 in particular has two oppositelydisposed flattened upper and lower surfaces 58, 59, whereby the distancebetween flattened surfaces 58, 59 is less than the distance betweenrounded-off lateral surfaces 56, 57 so that the tubular crosspiece 23has a flattened shape in the lengthwise direction of the chain. Lateralsurfaces 56, 57 and the corresponding undercuts 53, 54 are eachsubstantially semi-cylindrical. Tubular piece 23 is symmetrical, thatis, first and second lateral surfaces 56, 57 are symmetrical to eachother, upper and lower surfaces 58, 59 are symmetrical to each other,and the ends of the crosspiece are correspondingly symmetrical to eachother..Iaddend.

Referring to FIGS. 11 and 12, tubular piece 23 is insertable into recess50 by rotation around a longitudinal axis L when the second lateralsurfaces 57 at each end thereof are positioned in the second undercuts54 of the corresponding opposed recesses 50, whereby the longitudinalaxis interconnects centers of curvature defined by the semi-cylindricalsecond lateral surface 57. The assembly and removal of the tubularpieces 23 is best effected with a tool 51, the opening 52 of which fitsonto the profile of the tubular piece 23. In this embodiment of thefeeder chain, the chain links 49 on one side can be rapidly opened inorder to remove defective feed lines from the chain, or to place newfeed lines therein.

It should be noted that all of the individual parts of the inventiveguide or feeder chains can be made of a suitable plastic, or of a metal,especially a lightweight metal.

The present invention is, of course, in no way restricted to thespecific disclosure of the specification and drawings, but alsoencompasses any modifications within the scope of the appended claims.

What is claimed is:
 1. In a feeder chain for the supply of all types ofconsumable material to units that move on tracks, with said chaincomprising a plurality of chain links and having a continuous innerspace for feed lines, whereby said chain links have pivotablyinterconnected outer side pieces that are provided with stop means todelimit the mutual pivot angle, with each chain link being provided withtwo detachable crosspieces for interconnecting said outer side piecesthereof, the improvement wherein:said crosspieces are tubular pieces, atleast one of which is insertable via a force fit onto projections thatare disposed on facing sides of said side pieces, and one of saidtubular pieces is provided with a longitudinal slot, and the other ofsaid tubular pieces is unslotted, with said longitudinally slottedtubular pieces of all of said chain links being disposed on only oneside of said chain.
 2. A feeder chain according to claim 1, in whicheach of said tubular pieces has an approximately constant thickness, hastwo oppositely disposed flattened outer sides, and has two otheroppositely disposed rounded-off sides, whereby the distance between saidflattened sides is less than the distance between said rounded-offsides, with said projections having corresponding flattened sides thatare disposed parallel to longitudinal narrow sides of said outer sidepieces of said chain links.
 3. A feeder chain according to claim 1, inwhich said longitudinal slot is disposed on one of said rounded-offsides of said tubular piece.
 4. A feeder chain according to claim 1, inwhich said longitudinal slot is disposed on one of said flattened sidesof said tubular piece and has approximately the same dimension as thatflattened side in the longitudinal direction of said chain.
 5. A feederchain according to claim 4, in which one of said rounded-off sides ofsaid tubular piece is provided with a longitudinal groove.
 6. A feederchain according to claim 1, in which those projections of said outerside pieces that are associated with said longitudinally slotted tubularpieces are shorter than those projections that are associated with saidunslotted tubular pieces.
 7. A feeder chain according to claim 2, whichhas oppositely disposed end links in the form of connectors, each ofwhich has two outer side pieces connected by a tubular piece that isprovided with a securement lug for securement to a fixed connection or amovable consuming device.
 8. A feeder chain according to claim 7, inwhich said tubular pieces are made of a lightweight metal. .[.9. Afeeder chain according to claim 2, in which said outer side pieces ofsaid chain links are provided with recesses that are gated and providedwith undercuts in which one of said tubular pieces of each chain link isinsertable onto said projections; and in which the other of said tubularpieces is disposed in said recesses of said outer side pieces..]..[.10.A feeder chain according to claim 9, in which said other of said tubularpieces, after being placed in said recesses, are adapted to be securedto said outer side pieces in a positive and formlocking manner by beingrotated about their longitudinal axes..]..Iadd.11. In a feeder chain tounits that move on tracks, with said chain comprising a plurality ofchain links and having a continuous inner space for feed lines, whichchain links have pivotably interconnected outer side pieces that areprovided with stop means to delimit the mutual pivot angle, with eachchain link being provided with two crosspieces for interconnecting saidouter side pieces thereof, the improvement wherein:an outer side pieceof each chain link has at least one inwardly-facing recess therein,which recess has a gate and first and second undercuts next to saidgate; and one of said crosspieces of each pair is a detachablecrosspiece having a length between opposing ends thereof and a widthbetween a first lateral surface and a second lateral surface at one ofsaid ends of said detachable crosspiece, such that when said secondlateral surface of said detachable crosspiece opposite said firstlateral surface of said detachable crosspiece is positioned in saidsecond undercut of said recess, said first lateral surface of saiddetachable crosspiece is insertable into said gate via an elasticforce-fit when entering through said gate into said first undercut, thewidth of said one end of said detachable crosspiece between its firstand second lateral surfaces being greater than the width of said gate,whereby engagement between said first and second lateral surfaces andsaid first and second undercuts, respectively, retains said detachablecrosspiece in said recess..Iaddend..Iadd.12. A feeder chain according toclaim 11, wherein both ends of said detachable crosspiece have saidfirst and second lateral surfaces, and the ends of said detachablecrosspiece are each insertable into a pair of said recesses provided inopposing positions on each of the outer side pieces in each chain linknear the top of each outer side piece with each gate opening upwardly,the other of said two crosspieces being located near the bottom of eachouter side piece..Iaddend..Iadd.13. A feeder chain according to claim12, in which at least one of said first and second lateral surfaces ofsaid detachable crosspiece is substantiallysemi-cylindrical..Iaddend..Iadd.14. A feeder chain according to claim13, in which said detachable crosspiece is insertable by rotation ofsaid crosspiece around a longitudinal axis when said second lateralsurfaces of said detachable crosspiece are positioned in said secondundercuts of said recesses, whereby the longitudinal axis interconnectscenters of curvature defined by said semi-cylindrical second lateralsurfaces..Iaddend..Iadd.15. A feeder chain according to claim 12,wherein the detachable crosspiece is tubular..Iaddend.